Global Land Use
Posted by Stuart Staniford on June 2, 2006 - 11:45am
Major classes of global land use shown as stacked areas. Source: FAO.
| Russia | 1.71 |
| Canada | 1.00 |
| United States | 0.96 |
| China | 0.96 |
| Brazil | 0.85 |
| Australia | 0.77 |
| India | 0.33 |
| Argentina | 0.28 |
| Kazakhstan | 0.27 |
| Sudan | 0.25 |
These ten countries represent 53% of the non-Antarctica land area. If the European Union was a country, it would weigh in at 0.40 b.h. - slightly ahead of India, but far behind the bigger countries.
According to the FAO, the recent trends in global land usage are as follows.
Major classes of global land use shown as stacked areas. Source: FAO.
As you can see, it adds up to about the 13.4 b.h. expected. Unfortunately the data series for forests/woodlands and "All other land" end in 1994. These are the largest categories, with pasture land a little bit behind, and then arable land somewhat smaller and permanent crops (eg orchards, sugar cane) far behind again.
It's easier to get a sense of the trends (which are fairly slight) in individual classes by looking at a line graph:
Major classes of global land use shown as individual trend lines. Source: FAO.
There are steady but modest decreases in forests and other lands, and steady but modest increases in pasture land and arable land. Presumably, these trends are likely to continue as human population increases. But it's hard to see them radically accelerating, given that people are already using almost all the best land. Thus major changes in the production of the land would have to come from changing the productivity of it, not from expanding the area utilized.
Finally, the FAO has statistics of agricultural land (arable plus pasture plus permanent crops) that is irrigated. Here's what that graph looks like:
Percentage of arable land that is irrigated. Source: FAO.
As you can see, it's been going up pretty steadily, except for a leveling off in the last few years. Whether that leveling off is a temporary matter or something more serious, I don't know. I've been reading Lester Brown's Plan B lately; he's very concerned about water, but he doesn't present the evidence clearly enough for me to decide whether I agree with him or not.
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They estimate that these 11.2 billion ha capture at least 80-90% of the total usable annual generation of biomass.
The site includes a couple of figures showing the decline over time in biological capacity, due mostly to resource depletion and ecosystem degradation, and in the area occupied for agricultural crops. While data supporting the early part of the analyses are less reliable, the overall trends are probably more realistic than the ones above, which are based on incomplete data from the FAO.
Moreover, the Oil Civilization in fact has no water, it just spends a bit more energy in treating and bringing water to the big cities.
Coming to grips with "water" is probably as much an effort as learning about Peak Oil except that water is not burnt and thereby chemically converted into a GreenHouse Gas like CO2 (not to say that H2O is not a GHG itself, which it is.) Thus "water" can theoretically be recycled, which makes it sound like it's no big deal. It is a big deal. Wars are fought over water.
Jared Diamond's book, "Collapse" discusses how water can bring a civilzation to its knees.
The best case wet tropical environments have a net primary productivity of 9000kcal/year with yielded an estimate of 160m2 to grow a barrel of oil. I was asked for a more realistic case. Well, the best case palm oil plantations are said to produce 7250 litres/hectare/year. (No, I don't know how much fossil fuel fertilizers and chemicals are needed in the process) This is close to a limiting case where almost 3/4ths of the net primary productivity goes into palm oil production. So allowing for a few roads and barracks you could grow replacement for fossil fuels on "only" 15 million km2.
The trouble is that this exceeds 10% of the land area of the planet, and only wet tropical land will grow palm oil. In fact it is nearly double the entire area of Brazil. So only by destroying the entire tropical belt ecosystem (goodbye Amazon, Congo, Borneo) and genocide of the native populations (in excess of the slaves needed to work the palm oil plantations) would it be even in rough theory possible to grow even one crop of biofuels equivalent to fossil fuel use. I don't know what soil fertility of a palm oil plantation is like after years of harvesting this monocrop, but doubt it improves over time.
Rich baby boomers can relax, they should be able to get petrol enough to drive their 200 horsepower cars (think about that, this implies that your car should need 200 times as much land to grow food as a horse does!) until they retire. But please don't delude yourselves that your grandchildren will be able to do the same with biofuels. Here is the future of biofueled personal transportation: bicycle (maybe with small motor assist) for most folks, oxcarts on the farm, and for the rich folks a horse carriage to go into town
However, there is NOTHING we can do if we allowed continued population growth through immigration. And that includes not just transportation, but food production, housing, land preservation and everything else.
We have examples of processes which turn waste biomass into charcoal and fuel gas (which could feed Clostridium cultures to make liquid fuel), and we also have existence proofs of long-term sequestration of carbon and enhancement of soil properties by addition of charcoal to soil. We can get energy from biomass, enhance soil fertility and pull carbon out of the atmosphere; they are not mutually exclusive.
Don't misunderstand. I am in favor of plug-in hybrids at an indvidual level. (I want one, and I plan to build a home/farm wind-power station.) But it doesn't create any new energy. If we move as much weight as many miles, we'll need a LOT more electricity to do it.
Here's a paper that compares the relative "door to door" efficiency of gasoline vs. electricity:
http://www.evadc.org/pwrplnt.pdf
Annual US gasoline consumption is about 140 billion gallons; if we assume 22 MPG average, that's 3.08 trillion vehicle-miles. If we can drive 80% of that on electricity at 350 Wh/mile average, we'd need 862 billion kWh/year or around 22% of current US electric consumption; call it 98 GW average. If we added wind capacity at 20 GW/year and got 30% capacity factor, we'd add 6 GW/year average from wind. Wind would fill the electric demand from vehicles after about 17 years, which just happens to be the average lifespan of passenger cars in the US.
Note that the available wind power on the US continent is around 1.2 terawatts.
There are some issues which would have to be resolved to make this actually work minute-by-minute, but the broad level details of how much energy is available and so forth lead inevitably to the conclusion that this can be done. You can have your Hummer as long as it runs on Li-ion cells.
How about starting with the corn current going into ethanol production? One bushel of corn is used to produce 2.6 gallons of ethanol at 77000 BTU per gallon generates about 200000 BTUs. That corn contained ~400000 BTUs. If instead you took the corn to a power plant and used it to generate electricity you could power two plug-in hybrids with the corn used to power one E85 vehicle.
Unless one believes in gray aliens from Zeta Reticuli, there is no immigration. The earth is a spherical system which can be considered closed except that it absorbs sunlight and emits infrared. Climate change, peak oil and overpopulation are not easily contained by political barriers.
Peak energy, peak food, peak water: these are global problems. The solutions will be global over the long term, or they won't be solutions at all.
They're coming via the same route that we all did: they were born. But we can't force other regions of the world to make the changes to deal with their own overpopulation if we keep taking it off their hands. "Think globally, act locally."
Excuse me while I roll on the floor laughing.
Excuse me while I roll on the floor laughing.
This could save the day if we get our rears in gear.
Several thoughts:
- This has not been done on anything but a very small scale
- When we talk about an EROI (Energy Return on Investment), we usually assume its solely a return on Energy invested, but there are many inputs to an energy process: energy, land, water, labor, etc. So the EROEI may be very high for algae to oil but the water and land costs could be enormous making the scalability of it small
- Any alternative energy that has a huge energy payoff puts us in the dangerous position of creating more energy and thus more leverage for humans to build, buy, burn and excrete more stuff. We really are running up against environmental constraints, global warming being one of the more prominent but possibly not the greatest threat (food supply, ocean health, toxicity, etc). For a 20-30:1 new energy process to replace oil and gas may seem a boon on the surface, but the externalities of such a boon must be accounted for. This doesnt make the process itself bad (algae to liquid fuel) but what we do with the net energy gain.
As Lee Corso on ESPN says...."Not so fast my friend"..Someone else famous said "Be careful what you wish for, you might get it"
as reported in Scientific American
The solution is to use halophilic algae and just let the water evaporate; exchange with seawater to maintain the optimal salt concentration.
The first graph is labelled "Flows of carbon in biomass products..." but this does not match the graph.
"as you'll see, humanity is already using most of the land area "
Maybe I missed something, but I don't see where that is justified? It obviously depends on what is meant by "using", but it looks to me we are using perhaps 50%.
I don't what the FAO definition is, but the figures look more like how land is allocated. Land may be forested, but that doesn't necessarily mean it is being actively logged.
As you point out, the acreage doesn't mean much by itself, you also need to consider intensity of land use, which is probably a better metric. I think it is instructive to also look at Net Primary Production for example.
The two major increases in farmland have been due to the tractor and irrigation. My memory is the big arable land increases happened in the 70's. A good deal of this land is considered maginal & irrigation I imagine is the limiting factor.
So maybe gains in land-gardens, but larger size losses-land requiring irrigation. Add in global warming and rain loss for some of the Breadbasket of the world and I get concerned even for the US. Of course this would be disastrous for the grain importers.
I am skeptical about biofuels because I believe energy losses/EROEI would be so evident only military & the rich would attempt such & social disorder would be the bigger issue.
As we go through the dual effects of PO and GW we will see less production from our current ag land - less fuel for equipment, less manufactured fertilizer, less pesticides and less energy for irrigation. Throw in changes in weather patterns because of GW and you could have areas that are currently producing crops loose their water supply or have their rainfall amounts decreased to where they do not produce at the same levels.
Stuart was looking at ways to get energy out of the biosphere and sink CO2 into it. I don't think we are going to see great changes - increases anyway - in the amount of energy produced by our arable land or permanent pastures. These lands are already producing about as much as they can with traditional methods. If we are going to increase we need to reach into the 'other lands' with no traditional methods to gather energy - solar, wind, biofuel from alge.
I don't think we can afford to 'try' something new with our arable land right now, not until we find more sustainable ways of producing from that land. Then again, we may come to a point in the future where we cannot afford to not 'try' something new.
One last thing that I see in this information is that things do not change all that much over the past 40+ years, but we are getting more out of our arable land. What happens when that arable land starts going back to 'other land'?
Kevin
http://www.sciencemag.org/cgi/content/full/309/5734/570?ijkey=HWa5VDcwb/BEc&keytype=ref&site id=sci
Logistical peak food seems to be upon us. Since 2000, the trend is for consumption to be greater than production. We have significant stores, which we are now eating down.
This article says that the global food pantry has dwindled from 116 days in 2000 to 69 now, and may be just 57 days by year's end.
The president of Canda's National Farmer's Union has written this letter to Kofi Annan regarding this alarming decline.
My question is really about substitutes for fertilizer. If we predict that fertilizer will be increasingly scarce in the future, what are the substitutes? Do they scale up? Or what current demand for natural gas, which is used to create fertilizer, will be forgone?
Algae based Biodiesel vs. Cellulosic Ethanol
We would need more land than the USA has to produce enough ethanol. The desert and salty lakes are a great place to grow algae.
The United States has plenty of unutilised fallow farmland. But the energy return on planting crops for alcohol is marginal. So the only good answer is limiting the size of families to no more than two children which is below the replacemnt rate and giving up two cars per family. Not an easy sell. Six billion people is above the long term carrying capacity of our planet no matter what the Pope says
I was a bit disappointed as well, Stuart. Although
I was impressed with Lester's knowledge of
agriculture and water. His understanding of
economics is limited (in my view).
Have you ever looked into the Ecological Footprint analyses. I'd love to get your impression. There are two organizations doing these, and one just came out with a new study:
http://www.ecologicalfootprint.org is a really great way to take a tour of nations and compare their footprints. I was amazed that the US footprint is over 5 times our national biocapacity! This implies that to live within the resources of our nation (and to therefore adhere to the now popular cry of weaning us from our addiction to foreign oil) would minimally require a reduction in our resource consumption and pollution levels to a fifth of what they are today.
I interviewed the author of this report on May 8th and it can be found here:
http://www.globalpublicmedia.com/interviews/707
FYI, I interview Nate Hagens (thelastsasquatch) this Monday. Streaming from www.kzyx.org 9-10 PDT.
A general comment - the fact that social, economic, governance and population transitions have not begun leads me to remain highly pessimistic as to the future. I started my own transition 30 years ago and my expectation is that society will panic and make all the wrong choices attempting to maintain the status quo.
The definitive book on the subject is Wittfogel's "Oriental Despotism." He make a strong case that irrigation-based societies have in historical times been remarkably stable and powerful. Think Egypt. The reason is that irrigated land offered a solid and reliable EROEI.
The increase in irrigated acrage post-WWII has been due to exports of "pre-packed" energies from industrial societies to Third World countries. In ancient times, a society had to be able to bootstrap themselves into a fancy irrigation system by saving and reinvesting excess labor into dams and canals. Nowadays, we rich countries give them away.
Can we increase irrigated acrage? Probably not since we've reached a point of declining returns worldwide and certainly within the US.
As to the source of Stuart's statistics (the FAO), do you have alternate sources to check the UN figures? I've heard other statements that we've plenty of unused land worldwide.
99% of biomass is in plants, vs animals or microorganisms.
99% of plant biomass is in land plants, vs ocean plants.
I was surprised that plants are so dominant over animals in biomass. We often think of plants as something of an evolutionary dead-end, that animals have taken over, but in fact animals are almost negligible in the big picture.
I also had always thought of the oceans as being fertile, being where life originated and all, but actually I guess most of them are essentially deserted of life. The land adaptation really was a major evolutionary step forward.
Got this info from a forestry site of all places:
http://www.icsu-scope.org/downloadpubs/scope13/chapter06.html
A pond full of algae can have low algal biomass and be constantly eaten by fish, but have high productivity, meaning how much carbon and energy is captured and turned into living tissues.
Aquatic systems tend to have low standing biomass but can have high productivity.
On land, the fertile grasslands have high productivity and low standing biomass and are eaten by very big herds, e.g. ,bison and wildebeast.
If you want to think if it in terms of oil, you can have a small reservoir under high pressure with a fast rate of extraction or something like the tar sands, which are huge but have a low rate of extraction. But this is not a great analogy since these are non-renewable and will run out. Ecosystems don't tend to have that problem if left alone.
I don't inherently disagree. However, a significant amount of food, including meat (rabbit, chicken, fish) can be produced using a variety of techniques.
Find a copy of The Integral Urban House, ISBN 0-87156-213-8 for lots of details on growing food at home. For an overview, see:
http://www.motherearthnews.com/menarch/archive/issues/042/042-125-01.htm
I didn't check to see if the link still works.
I would also suggest Post Soviet Lessons for a Post-American Century:
http://survivingpeakoil.com/preview.php?id=soviet_lessons
where the value of the kitchen garden is shown.
People may not be able to produce all their food but anything may keep them from starving. Do I expect them to do it? No.
If nothing else, you stop shipping the water weight of fresh vegetables by truck (and sometimes air!).